This invention relates to concrete deck structures and methods of making same; and more particularly relates to a novel and improved reinforced concrete deck structure for bridges and to a novel and improved method of fabricating same.
Numerous types of reinforced concrete slabs have been devised as a part of structural assemblies, such as for example, for absorbing weight-bearing and moving loads. A typical application is in highway and railroad bridges where there is a need for a high strength deck structure which can be installed on top of the girders which form the upper span of the bridge.
Representative approaches to the construction of reinforced concrete slabs is U.S. Pat. No. 6,006,483 to Lee wherein the slab or deck is provided with a ribbed metal bottom plate and reinforcing bars are welded to lattice members which are in turn attached to a deck plate. U.S. Pat. No. 5,448,866 to Saito is directed to a solid metal pan formed of sheet steel with rebar affixed to the pan by strut members. U.S. Pat. No. 5,440,845 to Tadros et al provides a lower steel plate to support reinforcing bars as well as concrete in forming a reinforced concrete slab. Other patents of interest are U.S. Pat. No. 6,000,194 to Nakamura and U.S. Pat. No. 5,235,791 to Yaguchi.
It is desirable to provide for greatly enhanced structural stability in a reinforced concrete slab by employing a solid metal pan which is interposed between concrete layers of the slab and which further lends itself well to precasting in slab sections at a manufacturing site and then transporting to the desired installation site at which additional concrete layers can be poured to complete the assembly and in such a way as to eliminate separate lattice or strut portions as well as to achieve increased shear and compression strength.
It is therefore an object of the present invention to provide for a novel and improved reinforced concrete deck structure and method of fabricating same.
It is another object of the present invention to provide for a novel and improved reinforced concrete slab and to a method of making same in which the reinforcing layers are integrated into concrete layers of the slab in an improved, simplified and highly efficient manner.
A further object of the present invention is to provide for a reinforced concrete deck structure in which the reinforcement is composed of a solid metal pan in combination with reinforcing bars which will strengthen the deck structure both in compression and in shear.
It is a still further object of the present invention to provide for a novel and improved concrete deck structure for bridges and method of making same.
In accordance with the present invention, a reinforced concrete slab is made up of first and second layers of concrete in superimposed relation to one another and separated by a solid metal pan which has corrugations alternately extending into embedded relation to each of the layers. Preferably, reinforcing bars extend in spaced parallel relation to one another through the pan in a direction parallel to the layers but transversely of and through the corrugations or channels. The slab is specifically adapted for use as a deck for bridges, but has other useful applications.
A method of fabricating a reinforced concrete bridge slab to serve as a deck structure for a bridge which has a plurality of girders extending lengthwise of the bridge in accordance with the present invention comprises the steps of pouring a cementitious material into a generally rectangular form to a predetermined thickness and so as to cover a metallic pan in the bottom of the form having a plurality of corrugations or channels which are embedded into the first layer, inserting a plurality of reinforcing bars transversely of and through the corrugations or channels and through the first layer, and curing the first layer into a unitary reinforced concrete slab followed by turning the form over and removing the partially completed slab. After transporting the slabs to the installation site a second layer is applied after positioning the cured slabs on the girders with their pans exposed.
There has been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.